This invention relates in general to body and frame assemblies for vehicles. More specifically, this invention relates to an improved structure for a closed channel structural member, such as a side rail or a cross member, for use in such a vehicle body and frame assembly that includes an internal reinforcing structure to increase the strength and rigidity thereof.
Many land vehicles in common use, such as automobiles, vans, and trucks, include a body and frame assembly that is supported upon a plurality of ground-engaging wheels by a resilient suspension system. The structures of known body and frame assemblies can be divided into two general categories, namely, separate and unitized. In a typical separate body and frame assembly, the structural components of the body portion and the frame portion of the vehicle are separate and independent from one another. When assembled, the frame portion of the assembly is resiliently supported upon the vehicle wheels by the suspension system and serves as a platform upon which the body portion of the assembly and other components of the vehicle can be mounted. Separate body and frame assemblies of this general type are found in most older vehicles, but remain in common use today for many relatively large or specialized use modern vehicles, such as large vans, sport utility vehicles, and trucks. In a typical unitized body and frame assembly, the structural components of the body portion and the frame portion are combined into an integral unit that is resiliently supported upon the vehicle wheels by the suspension system. Unitized body and frame assemblies of this general type are found in many relatively small modern vehicles, such as automobiles and minivans.
Traditionally, the various components of vehicular body and frame assemblies have been formed from open channel structural members, i.e., structural members that have a non-continuous cross sectional shape (such as U-shaped or C-shaped channel members, for example). For example, it is known to use one or more open channel structural members to form the side rails, the cross members, and other components of a ladder frame type of separate body and frame assembly. To facilitate the connection of the body portion to the frame portion, a plurality of body mount support brackets are secured to the side rails of the frame portion. Such body mount support brackets have traditionally been formed from stampings that were bent or otherwise deformed to desired shapes to provide supports for the body mounts used to connect the various structural members of the body portion thereto. The use of such stamped body mount support brackets was relatively easy with traditional open channel structural members used to form the ladder frame assembly because both the stamped body mount brackets and the side rails were generally rectilinear in shape. However, the use of open channel structural members to form the various components of vehicular body and frame assemblies has been found to be undesirable for several reasons.
To address this, it has been proposed to form one or more of the components of the vehicular body and frame assemblies from closed channel structural members, i.e., structural members that have a continuous cross sectional shape (such as tubular or box-shaped channel members, for example). This cross sectional shape is advantageous because it provides strength and rigidity to the vehicle body and frame component. Also, in those instances where the vehicle body and frame component has a generally rectilinear cross sectional shape, vertically and horizontally oriented surfaces are provided that are well adapted to have the body mount support brackets discussed above secured thereto. Furthermore, closed channel structural member are well suited to be deformed to a desired shape by hydroforming, which is a well known process that uses pressurized fluid supplied within the closed channel structural member to deform it into conformance with a surrounding die. Hydroforming has been found to be a desirable forming process because portions of a closed channel structural member can be quickly and easily deformed to have a complex cross sectional shape.
Although closed channel structural members provide strength and rigidity to the vehicle body and frame component, there are instances where it is necessary or desirable to further increase the strength and rigidity thereof. For example, it may be necessary or desirable to reinforce the strength of a closed channel structural member at one or more locations throughout the length thereof to prevent deformation under extreme operating conditions, such as during a collision. Also, it may be desirable to reinforce the strength of a closed channel structural member at one or more locations throughout the length thereof where mounting brackets or other ancillary components are secured thereto. Because of their inherent closed cross sectional shape, however, it has been found to be difficult to provide such reinforcement in closed channel structural members, particularly without changing the shape of outer surface thereof.
Thus, it would be desirable to provide an improved structure for a closed channel structural member, such as a side rail or a cross member, for use in a vehicle body and frame assembly, that includes an internal reinforcing structure to increase the strength and rigidity thereof.
This invention relates to an improved structure for a closed channel structural member, such as a side rail or a cross member, for use in a vehicle body and frame assembly, that includes an internal reinforcing structure to increase the strength and rigidity thereof. Portions of the side rail are removed so as to provide an opening. This can be accomplished by forming two flanges that can be bent inwardly within the side rail to form the opening. A combined internal reinforcing member and mounting bracket is assembled to the side rail by moving it laterally such that a pair of side walls and an upper wall are inserted through the opening formed through the side rail until tabs provided on the side walls and the upper wall of the reinforcement member and mounting bracket abut the outer surface of the side rail. Then, portions of the reinforcing member and bracket are secured to the side rail by welding. When assembled with and secured to the side rail, the reinforcing member and bracket functions as a dual purpose member, providing structural reinforcement for the side rail and simultaneously providing a mounting point for an ancillary component of the vehicle, such as a shock absorber, body portion, and the like. If desired, the reinforcing member can function as a single purpose member, solely providing structural reinforcement for the side rail.